TCP/IP protocol suite layer and OSI model’s layer

IT Networking
and
Communication

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TCP/IP protocol suite layer and OSI model’s layer
Layers of TCP/IP layers are Network Access/Link layer, Process/Application layer, Host-to-
Host and Internet layer. At the same time, in order from bottom to top, the OSI layers are
Physical layer, Data Link Layer, Network layer, Transport layer, Session layer, presentation
layer and application layer respectively (Montreuil, Ballot and Fontane, 2012).
TCP/IP and OSI layer correlation
High degree of correlation exists between OSI layers and TCP/IP layers. Network layer of
TCP/IP model is a mixture of OSI model’s Physical and Data link layer as they have the
same function of looking out for addressing of protocols required for physical delivery of
data and also for addressing of hardware. Network layer of OSI model corresponds to internet
layer of TCP/IP. It suggests the rules that are necessary for logical delivery of data within the
network (Li, et al. 2011).
Transport layer of OSI layer corresponds to internet suite of TCP/IP layer. They are doing the
work of end-to-end communication and error-free data delivery. They protect upper-layer
applications from the complexity of data. Application, session and presentation layer of OSI
resembles to process layer in TCP/IP. They all have the role of describing details of the user-
interface and they do point-to-point communication (Edwards and Bramante, 2015).
Layers that are network support layers
Internet and Network layers are understood as network support layers in the TCP/IP protocol
suite while Host-to-Host and process layers are layers for user support.
Data encapsulation
Primary unit of information is packets. They are transported all across the network having
minimum numbers of headers and have sending and receiving host addresses as well as a
body along with the data that has to be moved. When packet goes through TCP/IP protocol
stack, each layer’s protocols either adds or removes fields from the primary headers (Alani,
2014). During this when protocol sends host add some data in the packet header, this process
is understood as data encapsulation.

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Data link layer responsibilities
This layer has a function of logical link control, physical layer standards, media access
control and handling, error detection and hardware addressing. It provides continuous data
transfer by distributing packets through required synchronisation as well as through flow and
error control. Data link layer is responsible for encoding bits into packets before transmission
and then decoding back the packets into bits at the target (Fall and Stevens, 2011).
Difference among Transport layer and Network layer delivery
Network layer overlooks individual packet’s host-to-host delivery while the transport layer is
responsible for process-to-process delivery of the entire message. Transport layer’s delivery
is linked with transferring all messages from source to destination where deliveries are both
connection oriented and connectionless. On the other hand Network layer delivery is linked
with packet transferring from source to destination through different networks (Edwards and
Bramante, 2015).
Another mechanism’s requirement for transport layer
Even when errors are spotted at transport layer, transport layer requires different mechanism
at the transport layer. This is because physical channels are used for communication among
two routers within the data link layer while in transport layer this physical channel is
substituted entirely by subnet (Li, et al. 2011). Within data link layer, specifying which
router, one router aims to communicate from each outgoing line. Due to this, they specifically
offer a panicular router. Within transport layer, explicit addressing for destination is required.
Such mechanism of another type assists in reduction of error due to transfer of data.
Network layer responsibilities
Operating IPs is the major responsibility of Network layer. It is accountable for routing i.e.
packet movement throughout the network by taking help of most suitable paths. It also
accounts to addressing the messages and interpreting logical addresses (IP addresses) into
physical addresses (MAC addresses). It is also responsible for protocol control like TCP/IP
protocol suite (Base of internet and other kinds of networks) (Townes, 2012).